Using Magnetized (Fe3O4 / Biochar Nanocomposites) and Activated Biochar as Adsorbents to Remove Two Neuro-Active Pesticides from Waters

Abstract

This work describes the removal of pesticides from water using activated and magnetized biochars produced from exhausted husk, and dry tannin from barks of black wattle (Acacia mearnsii De Wild.). These materials were characterized using chemical, spectroscopic, thermal, solid structure and surface area techniques. The activated and magnetized biochars were effective in removing the pesticides thiacloprid and thiamethoxam from both ultrapure water and Marcela Water Reservoir, Itabaiana, Sergipe State, Brazil. At the longest time examined, the amounts of thiacloprid and thiamethoxam adsorbed per gram of activated biochar adsorbent were 1.02 and 0.97 mg, respectively, while values of 0.73 mg (thiacloprid) and 0.40 mg (thiamethoxam) were obtained using magnetized biochar. A pseudo-second order model correctly described the kinetics of adsorption of both pesticides (R 2 ≥ 0.922). Desorption experiments revealed that the spent biochars could not be easily regenerated, which indicated that the forces holding the adsorbed fluid molecules to the solid surface were relatively strong.

Pristine and Magnetic Kenaf Fiber Biochar for Cd2+ Adsorption from Aqueous Solution

“…The magnetic biochar pattern's charac-teristics peaks at 42.5 • , 50.4 • , 53.7 • , and 57.8 • show the presence of Fe in the biochar. The Fe 3 O 4 phase was strongly crystalline and deposited on the composite's surface, as shown by the sharpness of the XRD peaks, and these findings are in agreement with studies done by Hongwei et al [73] and Tassya et al [74].…”

Characterization of Powdered Rhizophora Mucronata Bark Tannins Extractives using Different Drying Method s

“…6. The tannin powder proved to have an amorphous structure as their diffraction peaks emerge in the 2θ = 15° -30° range [43], [44]. The peaks that appear at around 2θ = 32°, 45° and 56° were comparable to the peaks of crystalline carbonaceous structure such as graphite.…”

Deashed Wheat-Straw Biochar as a Potential Superabsorbent for Pesticides

“…The amounts of pesticides adsorbed by each biochar were determined from the difference between the initial and final concentrations of the sorbates in the solutions, using the following equation [ 24 , 51 ]: Q = [(C 0 − C eq )·V]·m −1 [mg g −1 ] where Q is the adsorption capacity, expressed as mg of pesticide per g of biochar, C 0 is the initial pesticide concentration (mg L −1 ), C eq is the pesticide concentration at equilibrium, measured after 24 h of contact with the adsorbent (mg L −1 ), V is the volume of the solution used in the experiment (L), and m is the weight of biochar used (g).…”